Lighting is useful to illuminate areas and objects.
Many houses, businesses, rooms in houses, etc. use lighting fixtures. Often these lighting fixtures are in proximity to people and/or sensitive equipment. Often these lighting fixtures can radiate more than visible radiation. This radiation may present a problem.
For example, fluorescent lights driven by electronic ballasts emit incidental radio frequency radiation that must be limited according to regulations promulgated by various governments. If a fluorescent tube or the connecting wires conduct an oscillating current they will in general act as an antenna.
FIG. 1, generally at 100, shows how dual fluorescent tubes are typically connected to a ballast. At 102 is a power source (e.g. an alternating current (AC)) connected to a ballast 104 having common outputs 106 (denoted Y and Y) connected to fluorescent tubes 120 and 122 at one end, and the fluorescent tube 120 other end connected to ballast 104 outputs 110 (denoted B and B), and the fluorescent tube 122 other end connected to ballast 104 outputs 108 (denoted R and R). At 121 and 123 are representative current flows in fluorescent tubes 120 and 122 indicating they are in the same direction. This reinforces radiation emanating from fluorescent tubes 120 and 122.
FIG. 2, generally at 200, shows how dual fluorescent tubes are connected to a ballast with filaments in series. At 202 is a power source (e.g. an alternating current (AC)) connected to a ballast 204 having common outputs 206 (denoted O and O) connected to fluorescent tubes 220 and 222 with the respective filaments in series, and the fluorescent tube 220 other end connected to ballast 204 outputs 110 (denoted B and B), and the fluorescent tube 222 other end connected to ballast 204 outputs 208 (denoted R and R). At 221 and 223 are representative current flows in fluorescent tubes 220 and 222 indicating they are in the same direction. This reinforces radiation emanating from fluorescent tubes 220 and 222.